We inhale oxygen and exhale carbon dioxide. If we are stressed it is easy to over-breathe, to have a shallow breath and breathe often and the level of oxygen be too high compared to the level of carbon dioxide. It will be more difficult to relax and rest if these levels are imbalanced. In yoga there are several breathing exercises where you prolong the inhalation and/or the exhalation, or you add a pause. During this pause our body can adjust the levels or oxygen and carbon dioxide so that they are in balance again.
Below you find a breathing exercise that is called 6-6-9-3 that you can try on your own.
One type of breathing used in some breathing exercises in yoga is that you breath in through your nose and then hum out the air, as a bumblebee. When you breathe like this, larger levels of nitric oxide is released from your sinus. Nitric oxide is known to be antifungal, antiviral and antibacterial. A study at Karolinska University in Sweden has shown that this type of breathing will strengthen the immune system and help those that have problems with sinusitis.